cannot load such file -- util (LoadError)

[voxik]

I am trying to establish Ruby CI for Fedora using Fedora's Jenkins instance. What puzzles me is that the test runs quite often fails with errors such as [1]:

/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:54:in `require': cannot load such file -- util (LoadError)
    from /usr/share/rubygems/rubygems/core_ext/kernel_require.rb:54:in `require'
    from /chkbuild/chkbuild.rb:53:in `<top (required)>'
    from /usr/share/rubygems/rubygems/core_ext/kernel_require.rb:54:in `require'
    from /usr/share/rubygems/rubygems/core_ext/kernel_require.rb:54:in `require'
    from start-build:37:in `<main>'

This looks to me as some race condition. Any hint what could be the real reason behind?

[1] http://jenkins.fedorainfracloud.org/job/ruby-chkbuild/588/label=F22/console